/*
* Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
+ * Copyright (C) 2008 Alan Jenkins <alan-jenkins@tuffmail.co.uk>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
};
};
-#define TRIE_CHILD_MAX 10
-
struct trie_node {
+ /* this node's first child */
+ unsigned int child_idx;
+ /* the next child of our parent node's child list */
+ unsigned int next_child_idx;
+ /* this node's last child (shortcut for append) */
+ unsigned int last_child_idx;
unsigned int value_off;
- size_t value_len;
- unsigned char child_cur;
- unsigned char child_key[TRIE_CHILD_MAX];
- unsigned short child[TRIE_CHILD_MAX];
+ unsigned short value_len;
+ unsigned char key;
};
struct udev_rules {
size_t buf_max;
unsigned int buf_count;
- /* key strings are indexed to avoid wasting space with duplicates */
- struct trie_node *trie;
- unsigned short trie_cur;
- unsigned short trie_max;
- unsigned short *trie_root;
+ /* during rule parsing, strings are indexed to find duplicates */
+ struct trie_node *trie_nodes;
+ unsigned int trie_nodes_cur;
+ unsigned int trie_nodes_max;
- /* during rule parsing, we cache uid/gid lookup results */
+ /* during rule parsing, uid/gid lookup results are cached */
struct uid_gid *uids;
unsigned int uids_cur;
unsigned int uids_max;
return off;
}
-static unsigned char trie_child_slot(struct trie_node *node, char key)
-{
- unsigned char child_slot;
-
- for (child_slot = 0; child_slot < node->child_cur; child_slot++) {
- if (node->child_key[child_slot] == key)
- break;
- }
-
- return child_slot;
-}
-
static int add_string(struct udev_rules *rules, const char *str)
{
- struct trie_node *child;
- unsigned short child_off;
- unsigned short node_off;
+ unsigned int node_idx;
+ struct trie_node *new_node;
+ unsigned int new_node_idx;
unsigned char key;
- size_t len;
- int depth;
+ unsigned short len;
+ unsigned int depth;
unsigned int off;
+ struct trie_node *parent;
+ /* walk trie, start from last character of str to find matching tails */
len = strlen(str);
+ key = str[len-1];
+ node_idx = 0;
+ for (depth = 0; depth <= len; depth++) {
+ struct trie_node *node;
+ unsigned int child_idx;
- /* offset 0 is always '\0' */
- if (len == 0)
- return 0;
+ node = &rules->trie_nodes[node_idx];
+ off = node->value_off + node->value_len - len;
- /* strings with spaces are probably commands e.g. modprobe,
- with unique arguments. */
- if (strchr(str, ' ') != NULL)
- return add_new_string(rules, str, len + 1);
-
- /* descend root - start from last character of str */
- key = str[len - 1];
- node_off = rules->trie_root[key];
- depth = 0;
-
- /* descend suffix trie */
- if (node_off != 0) {
- while (1) {
- struct trie_node *node = &rules->trie[node_off];
- unsigned char child_slot;
-
- depth++;
- off = node->value_off + node->value_len - len;
-
- /* match against current node */
- if (depth == len ||
- (node->value_len >= len &&
- memcmp(&rules->buf[off], str, len) == 0))
- {
- return off;
- }
+ /* match against current node */
+ if (depth == len || (node->value_len >= len && memcmp(&rules->buf[off], str, len) == 0))
+ return off;
- /* lookup child node */
- key = str[len - 1 - depth];
- child_slot = trie_child_slot(node, key);
+ /* lookup child node */
+ key = str[len - 1 - depth];
+ child_idx = node->child_idx;
+ while (child_idx > 0) {
+ struct trie_node *child;
- if(child_slot == node->child_cur)
+ child = &rules->trie_nodes[child_idx];
+ if (child->key == key)
break;
-
- node_off = node->child[child_slot];
+ child_idx = child->next_child_idx;
}
+ if (child_idx == 0)
+ break;
+ node_idx = child_idx;
}
/* string not found, add it */
off = add_new_string(rules, str, len + 1);
- /* grow trie storage if needed */
- if (rules->trie_cur >= rules->trie_max) {
- struct trie_node *trie;
- unsigned short add;
+ /* grow trie nodes if needed */
+ if (rules->trie_nodes_cur >= rules->trie_nodes_max) {
+ struct trie_node *nodes;
+ unsigned int add;
/* double the buffer size */
- add = rules->trie_max;
+ add = rules->trie_nodes_max;
if (add < 8)
add = 8;
- trie = realloc(rules->trie, (rules->trie_max + add) * sizeof(struct trie_node));
- if (trie == NULL)
+ nodes = realloc(rules->trie_nodes, (rules->trie_nodes_max + add) * sizeof(struct trie_node));
+ if (nodes == NULL)
return -1;
- dbg(rules->udev, "extend string index nodes from %u to %u\n", rules->trie_max, rules->trie_max + add);
- rules->trie = trie;
- rules->trie_max += add;
+ dbg(rules->udev, "extend trie nodes from %u to %u\n",
+ rules->trie_nodes_max, rules->trie_nodes_max + add);
+ rules->trie_nodes = nodes;
+ rules->trie_nodes_max += add;
}
- /* insert new child node */
- child_off = rules->trie_cur;
- if (depth == 0) {
- rules->trie_root[key] = child_off;
+ /* get a new node */
+ new_node_idx = rules->trie_nodes_cur;
+ rules->trie_nodes_cur++;
+ new_node = &rules->trie_nodes[new_node_idx];
+ memset(new_node, 0x00, sizeof(struct trie_node));
+ new_node->value_off = off;
+ new_node->value_len = len;
+ new_node->key = key;
+
+ /* join the parent's child list */
+ parent = &rules->trie_nodes[node_idx];
+ if (parent->child_idx == 0) {
+ parent->child_idx = new_node_idx;
} else {
- struct trie_node *parent = &rules->trie[node_off];
- unsigned char child_slot = parent->child_cur;
-
- /* no space in parent, we can't index this string, nevermind */
- if (child_slot == TRIE_CHILD_MAX)
- return off;
+ struct trie_node *last_child;
- parent->child[child_slot] = child_off;
- parent->child_key[child_slot] = key;
- parent->child_cur = child_slot + 1;
+ last_child = &rules->trie_nodes[parent->last_child_idx];
+ last_child->next_child_idx = new_node_idx;
}
-
- /* allocate and construct the child node */
- rules->trie_cur++;
- child = &rules->trie[child_off];
- memset(child, 0x00, sizeof(struct trie_node));
- child->value_off = off;
- child->value_len = len;
-
+ parent->last_child_idx = new_node_idx;
return off;
}
if (rules->tokens == NULL)
return NULL;
rules->token_max = PREALLOC_TOKEN;
+
rules->buf = malloc(PREALLOC_STRBUF);
if (rules->buf == NULL)
return NULL;
rules->buf_max = PREALLOC_STRBUF;
- rules->trie = malloc(PREALLOC_TRIE * sizeof(struct trie_node));
- if (rules->trie == NULL)
- return NULL;
- rules->trie_max = PREALLOC_TRIE;
- rules->trie_root = calloc(UCHAR_MAX + 1, sizeof(unsigned short));
/* offset 0 is always '\0' */
rules->buf[0] = '\0';
rules->buf_cur = 1;
- /* offset 0 is reserved for the null trie node */
- rules->trie_cur = 1;
dbg(udev, "prealloc %zu bytes tokens (%u * %zu bytes), %zu bytes buffer\n",
rules->token_max * sizeof(struct token), rules->token_max, sizeof(struct token), rules->buf_max);
+ rules->trie_nodes = malloc(PREALLOC_TRIE * sizeof(struct trie_node));
+ if (rules->trie_nodes == NULL)
+ return NULL;
+ rules->trie_nodes_max = PREALLOC_TRIE;
+ /* offset 0 is the trie root, with an empty string */
+ memset(rules->trie_nodes, 0x00, sizeof(struct trie_node));
+ rules->trie_nodes_cur = 1;
+
if (udev_get_rules_path(udev) != NULL) {
/* custom rules location for testing */
add_matching_files(udev, &file_list, udev_get_rules_path(udev), ".rules");
rules->buf_max = rules->buf_cur;
}
}
- info(udev, "shrunk to %zu bytes tokens (%u * %zu bytes), %zu bytes buffer\n",
+ info(udev, "rules use %zu bytes tokens (%u * %zu bytes), %zu bytes buffer\n",
rules->token_max * sizeof(struct token), rules->token_max, sizeof(struct token), rules->buf_max);
- info(udev, "used %zu bytes of string index nodes (%hu * %zu bytes)\n",
- rules->trie_cur * sizeof(struct trie_node), rules->trie_cur, sizeof(struct trie_node));
+ info(udev, "temporary index used %zu bytes (%u * %zu bytes)\n",
+ rules->trie_nodes_cur * sizeof(struct trie_node),
+ rules->trie_nodes_cur, sizeof(struct trie_node));
/* cleanup trie */
- free(rules->trie);
- rules->trie = NULL;
- rules->trie_cur = 0;
- rules->trie_max = 0;
- free(rules->trie_root);
- rules->trie_root = NULL;
+ free(rules->trie_nodes);
+ rules->trie_nodes = NULL;
+ rules->trie_nodes_cur = 0;
+ rules->trie_nodes_max = 0;
/* cleanup uid/gid cache */
free(rules->uids);
return;
free(rules->tokens);
free(rules->buf);
- free(rules->trie);
- free(rules->trie_root);
+ free(rules->trie_nodes);
free(rules->uids);
free(rules->gids);
free(rules);
~ianmdlvl / elogind.git / blobdiff